Modern multiple-suite high-rise residential buildings have ventilation systems with floor or ceiling-embedded vent ducts. Each suite has one or more vent ducts. Exhaust conduits are used to connect exhaust air sources within the suite to one of the vent ducts. Bathroom fans, range hood fans and laundry dryers are typical exhaust air sources. For example, one exhaust conduit may be connected between the exhaust outlet of a bathroom fan and a vent duct, a second exhaust conduit may be connected between the exhaust outlet of a range hood fan and a vent duct, a third conduit may be connected between the exhaust outlet of a laundry dryer and a vent duct, etc. Exhaust air is expelled into the conduits and exhausted from the building through the vent ducts.
Conventional residential laundry dryers have built-in primary lint traps. However, a dryer's damp, warm exhaust air may contain a substantial amount of excess lint which is not trapped by the dryer's primary lint trap. A secondary lint trap can be coupled between the dryer's exhaust outlet and the building's vent duct to reduce the accumulation of lint in the vent duct.
A stackable laundry washer/dryer unit 10 (FIG. 1) incorporating a dryer 12 stacked atop a washer 14 is often used to conserve space in a high-rise building suite. FIG. 1 depicts two alternative prior art configurations for coupling dryer 12 to one or the other of prior art secondary lint traps 16A, 16B. As shown to the right in FIG. 1, dryer 12's exhaust outlet 18 can be coupled through conduit 20A, 90° elbow 22A and conduit 24A to the inlet 26A of prior art secondary lint trap 16A. Secondary lint trap 16A's outlet 28A is coupled through conduit 30A and 90° elbow 32A to ceiling-embedded vent duct 34A. Alternatively, as shown to the left in FIG. 1, dryer 12's exhaust outlet 18 can be coupled through conduit 20B, 90° elbow 22B, conduit 21B, 90° elbow 23B and conduit 24B to the inlet 26B of prior art secondary lint trap 16B. Secondary lint trap 16B's outlet 28B is coupled through conduit 30B and 90° elbow 32B to ceiling-embedded vent duct 34B.
It is generally recommended that no more than two 90° elbows and no more than 15 feet of conduit be used to connect a laundry dryer's exhaust outlet to a building-embedded vent duct. Otherwise, air pressure in the exhaust conduit(s) and vent duct is reduced, resulting in inefficient operation of the dryer and potentially necessitating installation of an inline fan (not shown) to increase air pressure in the exhaust conduit(s) and vent duct. The prior art configuration shown to the right in FIG. 1 is somewhat preferable to the configuration on the left, because the configuration on the right has only two 90° elbows 22A, 32A whereas the configuration on the left has three 90° elbows 22B, 23B, 32B. The configuration on the right is also preferable if the combined length of conduits 20A, 24A and 30A is less than the combined length of conduits 20B, 21B, 24B and 30B; particularly if the combined length of conduits 20B, 21B, 24B and 30B exceeds 15 feet.
It is not always possible to adopt a 2-elbow configuration like that shown to the right in FIG. 1, nor is it always possible to adopt a configuration requiring no more than 15 feet of conduit to connect a dryer's exhaust outlet to a suite's built-in vent duct. This is problematic because if moisture-laden air is not efficiently exhausted, moisture may accumulate inside the elbows, exhaust conduit(s), vent duct, etc. potentially causing water damage. Moreover, if a prior art secondary lint trap is mounted in a location which is difficult to reach, the suite's occupant(s) may be unable or may be disinclined to remove accumulated lint from the secondary lint trap with sufficient frequency. Lint may accordingly accumulate in the secondary lint trap to a point which further reduces the dryer's efficiency. In an extreme case, accumulated lint can pose a fire hazard.
The foregoing examples of the related art and limitations related thereto are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the drawings.